The present invention is related to powered apparatus for aerating or producing shallow holes along a ground surface.
It is often useful to "aerate" lawns and gardens by perforating the ground surface. This is done to allow the soil below to "breathe" and to allow moisture to be absorbed in the subsoil areas. Ground aeration is primarily performed on lawns where grass clippings and roots have caked along the ground surface preventing moisture from getting to the subsoil root areas.
Ground aerating has been accomplished both by hand and by power units. Hand aerating may be accomplished simply by pushing a pointed tool such as a pitchfork or special lawn aerating tool into the ground surface, then removing it to leave an exposed hole. This is a slow and tedious task, especially where large areas are to be aerated. Power aerators, on the other hand, operate to effectively aerate large surfaces. However, they are incapable of producing a uniform hole in the ground surface. Rather, they initially form a hole but tear through the ground surface as they are withdrawn, due to forward movement of the aerator framework.
Power aerators are known to include an eccentric drive or cam action mechanism by which the ground-penetrating members are moved substantially vertically into and out of the ground while simultaneously moving in a circular orbit. This action allows for formation of a smooth vertically oriented hole in the ground surface, at least theoretically. Actually, the forward motion is initiated at the precise time the penetrating members engage the ground surface. Both penetration and forward motion is imparted as the members are driven downwardly and rearwardly to move the aerator framework along a forward path. Similarly, retraction of the penetrating members occurs simultaneously with horizontal movement. The difficulty, then, is that the penetrating members do not have substantial purchase in the ground prior to the initiation of forward horizontal movement. They therefore tend to tear through the ground surface until they reach the point of maximum penetration. Then, as they are retracted from the ground surface, they again lose purchase and have a tendency to again tear through the ground surface.
It therefore becomes desirable to obtain some form of powered aerating device that will function to effectively produce holes in the ground surface without tearing through the adjacent soil and while simultaneously moving forwardly in response to horizontal movement of the ground penetrating members.